| Breast Cancers* | Woman-Years | Crude Rate | RR** | 95% CI |
---|---|---|---|---|---|
Attained Age | Â | Â | Â | Â | Â |
   55–59 | 274 | 63,088 | 434.31 | 1.00 | Ref. |
   60–64 | 608 | 108,640 | 559.65 | 1.36 | 1.18–1.57 |
   65–69 | 582 | 104,433 | 557.30 | 1.44 | 1.24–1.67 |
   70–74 | 434 | 79,134 | 548.44 | 1.48 | 1.26–1.73 |
   75+ | 187 | 34,419 | 543.30 | 1.47 | 1.21–1.79 |
Race | Â | Â | Â | Â | Â |
   White | 1,854 | 345,926 | 535.95 | 1.00 | Ref. |
   African-American | 89 | 19,765 | 450.29 | 1.05 | 0.84–1.32 |
   Asian/Pacific Islander | 111 | 17,230 | 644.23 | 1.14 | 0.86–1.51 |
   Other/unknown | 31 | 6,793 | 456.35 | 0.92 | 0.64–1.32 |
Family history of breast cancer | Â | Â | Â | Â | Â |
   No | 1696 | 336,410 | 504.15 | 1.00 | Ref. |
   Yes | 389 | 53,304 | 729.78 | 1.44 | 1.29–1.60 |
Number of Live Births | Â | Â | Â | Â | Â |
   0 | 240 | 35,545 | 675.20 | 1.00 | Ref. |
   1 | 160 | 28,296 | 565.45 | 0.70 | 0.55–0.89 |
   2 | 524 | 88,510 | 592.02 | 0.76 | 0.62–0.92 |
   3 | 526 | 96,163 | 546.99 | 0.75 | 0.62–0.91 |
   4 | 331 | 66,673 | 496.45 | 0.72 | 0.59–0.88 |
   5+ | 301 | 73,888 | 407.37 | 0.65 | 0.53–0.80 |
Age at First Birth | Â | Â | Â | Â | Â |
   None | 240 | 35,545 | 675.20 | 1.00 | Ref. |
   < 20 | 267 | 62,165 | 429.50 | 0.68 | 0.53–0.86 |
   20–24 | 901 | 181,709 | 495.85 | 0.74 | 0.59–0.91 |
   25–29 | 471 | 80,523 | 584.93 | 0.83 | 0.66–1.03 |
   30–34 | 148 | 20,822 | 710.79 | 1.03 | 0.81–1.31 |
   35+ | 47 | 6,894 | 681.75 | 1.02 | 0.74–1.41 |
Age at Menarche | Â | Â | Â | Â | Â |
   < 12 years | 457 | 76,987 | 593.61 | 1.00 | Ref. |
   12–13 years | 1099 | 209,082 | 525.63 | 0.86 | 0.77–0.97 |
   14–15 years | 439 | 84,595 | 518.94 | 0.85 | 0.74–0.97 |
   ≥ 16 years | 88 | 17,874 | 492.34 | 0.81 | 0.65–1.02 |
Age at Menopause | Â | Â | Â | Â | Â |
   < 45 years | 123 | 25,254 | 487.05 | 1.00 | Ref. |
   45–49 years | 340 | 64,113 | 530.31 | 1.07 | 0.87–1.31 |
   50–54 years | 700 | 126,080 | 555.20 | 1.12 | 0.92–1.35 |
   55+ years | 211 | 32,192 | 655.44 | 1.29 | 1.03–1.62 |
   Surgical menopause | 574 | 122,386 | 469.01 | 0.84 | 0.69–1.02 |
   Radiation/medication | 94 | 12,061 | 779.37 | 1.32 | 1.01–1.74 |
Menopausal hormone therapy use | Â | Â | Â | Â | Â |
   Never | 571 | 134,329 | 425.08 | 1.00 | Ref. |
   Former | 280 | 64,773 | 432.28 | 1.02 | 0.88–1.18 |
   Current, < 5 years | 372 | 61,931 | 600.67 | 1.44 | 1.26–1.66 |
   Current, ≥ 5 years | 847 | 125,006 | 677.57 | 1.67 | 1.49–1.87 |
Weight (kg) | Â | Â | Â | Â | Â |
   < 60 | 437 | 82,961 | 526.75 | 1.00 | Ref. |
   60 – 64.9 | 310 | 59,068 | 524.82 | 1.03 | 0.86–1.19 |
   65 – 69.9 | 311 | 56,091 | 554.46 | 1.18 | 0.97–1.30 |
   70 – 74.9 | 257 | 49,325 | 521.03 | 1.08 | 0.92–1.26 |
   75 – 79.9 | 267 | 47,072 | 567.22 | 1.21 | 1.03–1.42 |
   ≥ 80 | 486 | 91,892 | 528.88 | 1.20 | 1.04–1.38 |
Height (m) | Â | Â | Â | Â | Â |
   < 1.60 | 527 | 101,460 | 519.42 | 1.00 | Ref. |
   1.60 – 1.64 | 605 | 117,236 | 516.05 | 1.01 | 0.89–1.13 |
   1.65 – 1.69 | 561 | 102,205 | 548.90 | 1.06 | 0.94–1.20 |
   ≥ 1.70 | 385 | 66,707 | 577.15 | 1.11 | 0.97–1.27 |
BMI (kg/m2) | Â | Â | Â | Â | Â |
   < 18.5 | 25 | 5,135 | 486.85 | 0.88 | 0.59–1.32 |
   18.5 – 24.9 | 848 | 154,447 | 549.06 | 1.00 | Ref. |
   25 – 29 | 712 | 133,799 | 532.14 | 1.06 | 0.95–1.17 |
   30 – 34.9 | 305 | 59,109 | 516.00 | 1.10 | 0.97–1.26 |
   ≥ 35 | 173 | 32,478 | 532.67 | 1.21 | 1.02–1.43 |